Rotary pump or motor



Oct. 26, 1965 R. E. TRICK 3,213,799

ROTARY PUMP OR MOTOR Original Filed Dec. 26, 1962 2 Sheets-Sheet 2 A INVENTOR. Rosa-E7- E. 772/04 llllll lllllllllllV/l/l/gI/l/ll/IA i2 United States Patent 3,213,799 ROTARY PUMP 0R MOTOR Robert E. Trick, Racine, Wis, assignor to Webster Electric Company, Racine, Wis, a corporation of Delaware Continuation of application Ser. No. 247,174, Dec. 26, 1962. This application Apr. 16, 1965, Ser. No. 451,094 28 Claims. ((31. 103126) The present application is a continuation of Trick application Serial No. 247,174, filed December 26, 1962, now abandoned, and assigned to the same assignee as the instant application. The present invention relates to rotary hydraulic units such as pumps and motors and has for its primary object the provision of a new and improved high pressure rotary hydraulic unit.

A further object of the invention is the provision of a new and improved rotary hydraulic unit of the type including wear or end plate means that is pressure biased axially against impeller means, such as the gears of a gear pump.

Another object of the invention is the provision of a new and improved rotary hydraulic unit including wear or end plate means that is pressure biased in a radial direction toward the low pressure side, such as the inlet side of a pump.

A still further object of the invention is the provision of a new and improved rotary hydraulic unit, such as a gear pump, having both axially and radially biased end plate means, whereby high pressure operation of the unit is facilitated and made more eificient.

A further object of the present invention is the provision of a new and improved radially balanced rotary hydraulic unit of the gear type.

Another object of the invention is the provision of a new and improved rotary hydraulic unit of the gear type having reduced operating friction and consequent reduction in driving torque during operation.

Yet another object of the invention is to provide a new and improved unitary Wear plate sealing gasket assembly.

In brief, the present invention provides a rotary hydraulic unit such as a gear pump, that operates efiiciently at high pressures. The pump may take the form of a gear pump having a housing defining a gear chamber in which are located a pair of intermeshing gears constituting impeller means. The pump may include a fixed wear plate means and an axially movable wear plate means that is constructed and arranged in accordance with the present invention. The wear plate means may be a plate mounted in the chamber and one side of which abuts the gears and the second side is open to a pressure chamber. The second side has abutting against it unitary and integral sealing means or gasket encircling the wear plate and the major portion of the gear supporting shafts and means such as the bearing means supporting the shafts and dividing the pressure chamber into two areas, one subjected to high, such as discharge, pressure and the other to inlet pressure. These areas are so located as to force or bias the wear plate axially against the gears at a variable pressure corresponding to the discharge pressure, and thus to maintain the wear plate against the gears to prevent leakage at high pressures without undue binding. The wear plate itself is constructed so that it is also forced or biased toward the inlet side of the pressure chamber by discharge pressure so as to provide adequate sealing of the pump inlet. The sealing means is further constructed and arranged relative to the gear shaft supporting means as to provide an initial bias of the wear plate toward the inlet. This is accomplished as by loeating bearing means encircling portions of the sealing means eccentrically relative to the means. Additionally, the wear plate is so constructed as to provide radial balancing of the gears over considerable angular extents K 3,213,799 Patented Oct. 26, 1965 whereby bearing loadings and deflection of the gear shafts are considerably reduced. This is accomplished by opening the peripheries of the gears to discharge pressure over the major portions of their peripheries, whereby these pressures are balanced and the resulting reduced pressures force the gears toward the pump inlet. Further, a re duction in driving torque is achieved by constructing the axially biased wear plate means so that it does not en gage the gear teeth over a considerable angular extent and also by providing radial clearance beyond and over the full width of the tips of the gears over a considerable angular extent at the high pressure region.

Further objects and advantages of the present invention will become apparent from the ensuing description of an illustrative embodiment of the invention, in the course of which reference will be had to the accompanying drawings, in which:

FIG. 1 is an elevational view of a rotary hydraulic unit, illustrated as a gear pump, constructed in accordance with the present invention;

FIG. 2 is an enlarged axial fragmentary cross sectional view of the pump, the view being taken along the line 22 of FIG. 1;

FIG. 3 is a transverse cross sectional view, on a reduced scale, taken along the line 33 of FIG. 2;

FIG. 4 is a transverse cross sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a transverse cross sectional view taken along the line 55 of FIG. 4;

FIG. 6 is an elevational view of the pressure chamber side of the Wear plate gasket assembly of the present invention, the view corresponding to one along the line 6-6 of FIG. 2;

FIG. 7 is a fragmentary cross sectional view along the line 7-7 of FIG. 6;

FIG. 8 is a fragmentary cross sectional view along the line 88 of FIG. 4 and with the pump gears removed; and

FIG. 9 is a perspective view of a filler plate associated with the wear plate sealing means.

Referring now to the drawings, the rotary hydraulic unit of the present invention is indicated as a whole by reference character 10. It is shown as a gear pump including a housing 12 and impeller means 14 taking the form of intermeshing driving and idler gears 16 and 18.

The pump housing 12 includes opposed sections 20 and 22 having meeting faces 20A and 22A and held in assembled relation by a plurality of bolts 24 and accurately located relative to each other by dowels 26. A pumping chamber 28 is formed at the face 20A of housing section 20 and a pressure chamber 30 is similarly formed in section 22. The pumping chamber has a somewhat S-shaped configuration.

Pump gear 16 is rotated by a drive shaft 32 journalled for rotation in stationary structure such as the bearing means 34 and 3e mounted in counterbore 38 in section 20 and opening 40 in section 22, respectively. Bearing means 36 has an outer race or shell that projects into pressure chamber 30, as may be noted from FIG. 2. The idler pump gear 18 is driven by gear 16. Gear 18 is mounted on shaft 42 and the later is journalled on hearing means 44 and 48 in housing sections-20 and 22, respectively, and of which the outer race of bearing means 48 projects into pressure chamber 30. The gears may be made integral with their shafts or otherwise suitably secured thereto.

The pump is illustrated with an inlet 50 and an outlet 52, both in housing section 20. Inlet 50 communicates with the pump chamber 28 through passageway 50A. Outlet 52 communicates with the discharge side of the pump chamber 28 through passageway 50A. Outlet 52 communicates with the discharge side of the pump chamber 28 through passages 52A, 52B, 52C and 52D. Passages 50A and 52D lead to the inlet and outlet sides of the mesh point of the gears, the latter lying on a line passing through the axes of rotation of the gears, as best shown in FIG. 3, and with the gears rotating in the direction of the arrows in this figure.

In order to provide the axial loading of the present invention, the pump is provided with fluid pressure actuated wear plate means 60 acting axially on at least one side of the gears. In the present instance one such means is utilized, it being in the form of a wear plate 62 acting on the left side of gears 16 and 18, as viewed in FIG. 2. A wear plate 64 is shown at the right sides of the gears, it being at what might be termed the back side of pumping chamber 28 where it is relatively fixedly held and located by a close fit between its relatively short peripheral portions 64A and 64B and the adjacent side walls of the pressure chamber (see FIG. 3). The plate 64 is apertured at 66 with substantial clearance of the gear shafts 32 and 42. This plate is also inset somewhat in between the peripheral projections and cut away at the regions of the inlet and outlet passage portions 50A and 52D to give it a somewhat 8-shaped configuration. It should be noted that the fixed or dead wear plate 64 need not be used, as the gears could instead bear against the pump housing.

The axially movable wear plate 62 has a modified figure 8 configuration that is best illustrated in FIGS. 4 and 6. It is apertured at 68 with substantial clearance for the passage of shafts 32 and 42 and it is axially movable in the pumping chamber 28. It, too, is cut away at the region of the inlet and outlet to the pumping chamber, as indicated by reference characters 62A and 62B. It includes upper and lower portions that are identical and encircle shafts 32 and 42.

In order to reduce the bearing loading and shaft deflection, there is provided radial balancing means applying a uniform pressure, in this case discharge pressure, over a considerable angular extent of each of the gears. This is accomplished in two ways. The first is by constructing the wear plate 62 with inset portions 62C extending from the outlet cut away portion 62B in opposite directions toward the inlet portion 62A and up to plate portions 62D which project radially to abut against sealing surfaces 28A provided in the pumping chamber. The second feature contributing to radial balancing and more to reduction of frictional losses is the relieving of the pumping chamber around considerable angular portions of the gears at opposite ends of the chamber, as indicated by reference character 28B. This relieving provides short angular pumping chamber portions 28C abutting the gears near the outlet but these portions need not be used. Actually, they provide no sealing and are used only for measurement purposes during construction. They have an arcuate extent such that they do not seal from gear tooth to tooth. They also provide chamber surfaces opposite plate portions 64B. It should be noted that the relieved portions 283 have a considerable angular extent as do the cut away portions 62C. Cutting the wear plate away also contributes to a reduction in friction losses. The wear plate is not only cut over a considerable angular extent, but it is cut substantially to the roots of the gears as may best be noted from FIG. 2. Accordingly, the torque necessary to drive the pump during operation is reduced.

The wear plate 62 is biased axially against the gears by high pressure fluid, specifically fluid at discharge pressure. This is accomplished by placing pressure chamber 50 in communication with the discharge passage 52 thisbeing done through passage portion 52D and the inset portions 62B and 62C of the wear plate. The discharge pressure is limited to a first and generally E-shaped high pressure area or region 70 of the pressure chamber which is generally E-shaped and generally coextensive with portions 62B and 62C of the Wear plate. This is accomplished through resilient sealing means, such as the gasket indicated generally by reference character 72 in cooperation with the bearing cages 36 and 43. This arrangement also provides a second and low pressure region '74 that is subject to inlet pressure through cut away portion 62A of the wear plate 62.

The resilient sealing means 72 includes a peripheral generally elliptical portion 76 encircling in spaced relation the wear plate 62 and which fits into the pressure chamber 30 and seals portions of both pressure regions '76 and 74. While encircling the wear plate 62, the sealing means is disposed to one side of the plate. The elliptical portion 76 of the sealing ring has a generally T- shaped cross section, best illustrated in FIG. 7. It thus includes a straight inner portion 76A and a portion 763 that is compressed between housing sections 20 and 22, thereby effectively sealing the pressure chambers.

The sealing means 72 includes further integral straight transverse portions 720 extending inwardly to generally C-shaped portions 72D encircling the major portions of the peripheries of the bearing means 36 and 48 and another short straight portion 72E connecting the adjacent ends of the portions 72D. These portions are flat at their wear plate sides and beaded at their opposite sides.

In accordance with a feature of the invention, the wear plate and sealing means are constructed as a unit by bonding the two together. This facilitates manufacture of the wear plate assembly and assembly of the pump as a whole.

The high pressure region 70 is thus defined by the portions 76, 76C, 72D and 72E of the sealing means 72. The high pressure is thus applied over about 270 of the peripheries of the gears 16 and 18 to provide the radial balancing, as well as forcing of the gears in directions indicated by the converging arrows 79. The forces acting in these directions are minimized by reason of the fact that, in large part, the forces acting on the gears are equal and opposite. The resulting forces also bias the gears against the pumping chamber surfaces 28D, whereby the high pressures in the pump are effectively sealed from the low pressures.

The wear plate is also biased by the pump discharge pressure toward the inlet to effect sealing engagement between the wear plate regions 62D against surfaces 28A. Leakage is accordingly effectively prevented.

To prevent leakage initially as the pump is started, the wear plate is mechanically and resiliently biased in novel manner against the pump chamber. This is done by 10- cating the circular sealing means portions 72D eccentrically relative to the bearing means 36 and 48, so that portions of portions 72D of the sealing means force the wear plate toward the inlet. The eccentricity is best illustrated in FIG. 6 to which reference is now had. It will be noted that the centers of apertures 68 and bearing means 36 and 48 (and of the peripheries of portions 62D of the wear plate and pump housing surfaces 28A) are indicated by reference character 80. The centers of the curved portions 72D of the sealing means, indicated by reference characters 82, that engage the bearing means are displaced to the right a short distance as indicated by reference character 84. This illustration of FIG. 6 as to the eccentricity has been exaggerated-actually, the eccentricity need be but a few thousandths of an inch, such as about five to ten thousandths. The result of the eccentric location of the sealing means portions 72D is that, upon assembly, the portions 72 encircle and engage the bearing means more at the left (as viewed in FIG. 6) and consequently, the wear plate being bonded to the sealing means is forced to the left. Thus, the abutting wear plate surfaces 62D and housing surfaces 28A are resiliently held in sealing engagement so that the pump will initially operate satisfactorily as the pump pressure builds up, the wear plate is forced to the left to provide additional sealing at the abutting surfaces. The plate is forced to the left as a result of discharge pressure acting at the peripheral edge of Wear plate 62 at its insert portion 62C. Accordingly, leakage of fluid from inlet to outlet is effectively prevented.

The low pressure region 74 is defined by portions of the bearing means 36 and 48 that are not encircled by sealing means, a straight portion of the peripheral sealing means 76 and the straight portions 72C and 72E of sealing means. This region is open to inlet pressure through the cut away portion 62A of plate 62.

Collapse of the sealing means under high pressure is prevented by a block 90 overlying and spaced from the low pressure region of the wear plate. The block is provided with an aperture 90A leading to recess 92, which may be connected to the inlet or provide communication to the inlet from elsewhere, as may be desired at times, alternatively it may be imperforate. The wear plate side of block 90 is undercut at 90B to insure that the inlet pressure is available and effective at the pressure chamber side of plate 62. The undercutting provides feet 90C at the wear plate side (see FIGS. 4 and 8) that seat on the plate.

The block 90 may be made of some slightly resilient material, such as nylon. It is constructed so as to be insertable into the low pressure region and held in assembled relation by peripheral grooves 96 in it and lips 98 in sealing means portions 92C and 92E that fit into the grooves. The grooves 96 are formed in part by lips 100 that normally project beyond the plane of the block, as best shown in FIG. 8, thereby effectively to prevent extrusion of the sealing means and to insure adequate sealing without compression of the block itselfthe block thickness being somewhat less than the space between wear plate 62 and adjacent Wall of the pressure chamber 30, as best illustrated in FIG. 8. The block 90 also cooperates to provide additional sealing at the bearing means at the low pressure area, this sealing being provided by arcuate block portions 90D (see FIG. 9) which engage portions of the peripheries of the bearing means (see FIG. 4).

In construction of the pump, the housing sections and gears and their supporting shafts may be made in conventional manner. The fixed or dead wear plate 64 is inserted into the housing section 20, where it is located between one side of the gears and the housing. The pressure loaded end plate 62 is constructed as a unit with the sealing means 72, the two being bonded together. Thereafter, the block 90 is inserted into the low pressure region of the latter where it engages the sealing portions 72C and 72E and also a peripheral portion 76. The wear plate sealing means is then assembled at the second side of the gear plate, where it is peripherally held between the housing sections 20 and 22 with the portion 72 providing sealing between the two sections. The sealing means provides the high pressure area 70 and the second and low pressure area 74. The high pressure area is in communication with the gears by virtue of the inset portion 62C whereby the Wear plate is radially biased by the fluid pressure acting on the edge of the wear plate and also on the high pressure sides of portions 72D and 72E which are bonded to the wear plate. The insetting of the wear plate and the spacing 28B around the peripheries of the gear teeth and housing reduces the friction losses. The end plate 62 is also axially biased against the sides of the gears, the fluid pressure acting on the sides of the exposed portion of the plate beyond the sealing portions 72C, 72D and 72E. Initially, the wear plate is biased radially to maintain the wear plate portion 62C in sealing engagement with the housing portions 28A by the eccentric location of the sealing portion 72D relative to the bearing means 40 and 48. Accordingly, the pump is provided with both radial and end loading and the described construction has been found to be very effective with high pressures such as in the range of 2500 to 3000 p.s.i.

While the present invention has been described in connection with the details of an illustrative embodiment thereof, it should be understood that these details are not intended to be limitative of the invention except insofar as set forth in the accompanying claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller means, transversely and axially movable wear plate means having a first side movably abutting against a side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, the periphery of said wear plate means being inset from the housing substantially to the roots of the gears for a considerable angular extent in the high pressure area, whereby the pressure in said high pressure area biases the wear plate transversely in the direction of the low pressure area and the peripheries of the gear teeth are opened to the high pressure to provide radial balancing of pressures acting on the gears and reduction in driving torque.

2. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller means, transversely and axially movable Wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for eifecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means abutting the inside of the housing at the inlet side, and means including said resilient sealing means for biasing the wear plate transversely toward the inlet side of the housing.

3. In a rotary hydraulic machine, a housing having inlet and outlet regions, impeller means in said housing, a single transversely movable wear plate having a first side movably abutting against a first side of said impeller means and a second side and portions engaging the housing between the inlet and outlet regions, and means including resilient sealing means at the second side of said plate and acting upon the plate for biasing the Wear plate in a transverse direction to maintain said portions in engagement with the housing.

4. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller means having inlet and outlet sides, means including stationary structure on the housing for rotatably supporting said impeller means, transversely and axially movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for eflecting movement of said wear plate means relative to the impeller means, means including resilient sealing means secured to the second side of said plate providing high and low pressure areas at the second side of the plate, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means abutting the inside of the housing at the inlet side, and means including portions of said resilient sealing means eccentrically disposed relative to and engaging said stationary structure for biasing the wear plate transversely in abutment with the inlet side of the housing.

5. Ina rotary hydraulic machine as claimed in claim 4, wherein said stationary structure is constituted by hearing means.

6. A rotary hydraulic machine, a two part housing, impeller means including a pair of meshed gears in said housing, shafts for supporting the gears, means including bearing means in the housing for supporting the shafts, wear plate means apertured for the passage of the shafts having a first side transversely and axially movably abutting against a side of said impeller means and a second side spaced from and facing the housing, means including a pressure chamber at the second side of said plate for effecting movement of said wear plate means, means including resilient sealing means at the second side of said pressure chamber defining high and lower pressure regions at the second side of the plate, passage means connecting said high and low pressure areas to low and high pressure regions, respectively, of said impeller means, said sealing means including a first peripheral portion engaged between sections of the housing, and generally C- shaped portions extending from the peripheral seal portion from opposite sides of the inlet passage around considerable of the bearing means and an interconnecting portion betwen the bearing means.

7. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller means, wear plate means having a first side transversely and axially movably abutting against a side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate and for biasing the wear plate in a transverse direction toward the low pressure area to seal the latter area, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, the periphery of said wear plate means being substantially inset from the housing for a considerable angular extent in the high pressure area, whereby high pressures in the high pressure area bias said wear plate transversely toward the low pressure area to seal the latter area.

8. A rotary hydraulic machine, a two part housing, impeller means including a pair of meshed gears in said housing, inlet and outlet openings in said housing to said impeller means, shafts for supporting the gears, means including bearing means in the housing for supporting the shafts, a transversely and axially movable Wear plate apertured for the passage of the shafts and bearing having a first side movably abutting against a side of said impeller means and a second side spaced from and facing the housing, means including a pressure chamber at the second side of said wear plate for effecting movement of said plate, means including unitary resilient gasket sealing means bonded to the second side of said pressure chamber defining high and low pressure regions at the second side of the plate, passage means connecting said high and low pressure areas to low and high pressure regions, respectively, of said impeller means, said sealing means including a first peripheral portion engaged between sections of the housing, generally C-shaped portions extending from the peripheral seal portion from opposite sides of the inlet passage around and engaging considerable of the bearing means and an interconnecting portion between the bearing means, said wear plate being substantially inert from the housing for a considerable angular extent in the high pressure area and having portions extending from the ends of the inset toward the inlet and in sealing relation to the housing, whereby said wear plate is pressure biased to seal with the housing and high pressure is applied to the peripheries of the gears to provide radial pressure balancing, said C-shaped portions of the sealing means being eccentrically located relative to the bearing means to provide transverse resilient biasing of the wear plate toward the inlet to seal the said portions of the Wear plate against the housing, and said housing being spaced from the gear tips for a considerable angular extent in the high pressure area and the inset of the Wear plate being substantially to the roots of the gears.

9. A wear plate sealing assembly for end loading impeller means of a rotary hydraulic machine having a multipart housing and spaced bearing means supporting the impeller means, comprising a Wear plate having spaced peripheral portions for engagement with the housing and movable to abut against the impeller means and integral resilient sealing means bonded to a side of the wear plate opposite the impeller means to facilitate manufacture and assembly and adapted to define with the housing high and low pressure regions, said sealing means including a first and unsecured peripheral portion adapted to be engaged between parts of the housing, and a pair of generally C-shaped portions integral with and each extending from the peripheral seal portion inwardly along the spaced peripheral portions of the wear plate to and around considerable of the peripheral portions of the bearing means and a further portion interconnecting the C-shaped portions between the bearing means, said C-shaped and further portions having fiat portions that are bonded to the Wear plate.

10. An assembly as claimed in claim 9 wherein said sealing means is also generally rectangular in cross section.

11. A rotary hydraulic machine as claimed in claim 6 wherein said resilient sealing means is integral in construction.

12. In a rotary hydraulic machine, a housing having inlet and outlet regions, impeller means in said housing, a transversely movable wear plate having a first side movably abutting against a first side of said impeller means and a second side and a periphery that is inset from the housing over a considerable portion of the outlet region and with spaced portions engaging the housing between the inlet and outlet regions, and means including resilient sealing means at the second side of said wear plate and acting upon the plate for biasing the plate in a transverse direction to maintain said portions in engagement with the housing.

13. In a rotary hydraulic machine, gear type impeller means and spaced shafts therefor, a two part housing for said impeller means having inlet and outlet regions and having bearing means for supporting said shafts, movable wear plate means apertured for the passage of said shafts and having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, said wear plate means being peripherally inset from the housing over a considerable portion of the outlet region and having spaced portions engageable with the housing between the inlet and outlet regions, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, sealing between the two parts of the housing and around said bearing means, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said sealing means having a peripheral portion providing the sealing between the two parts of the housing and another portion with a fiat side bonded to the Wear plate means around a major portion of and between the bearing means and along the said spaced portions to where said other portion connects with the peripheral portion.

14. In a rotary hydraulic machine, gear type impeller means and spaced shafts therefor, a two part housing for said impeller means having inlet and outlet regions and having bearing means for supporting said shafts, movable wear plate means apertured for the passage of said shafts and having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing both the housing and the bearing means, said wear plate means being peripherally inset from the housing over a considerable portion of the outlet region and having spaced edge portions engageable with the housing between the inlet and outlet regions, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient and compressible sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, sealing between the two parts of the housing and around said bearing means, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said sealing means having a peripheral portion providing the sealing between the two parts of the housing and another portion bonded to the wear plate means around a major portion of and between the bearing means and along the said spaced portions to where said other portion connects with the peripheral portion.

15. A wear plate sealing assembly for end loading impeller means of a rotary hydraulic machine having a multipart housing and spaced bearing means supporting the impeller means, comprising a wear plate having spaced peripheral edge portions for engagement with the housing and movable to abut against the impeller means and integral resilient and compressible sealing means bonded to a side of the wear plate opposite the impeller means to facilitate manufacture and assembly and adapted to define with the housing high and low pressure regions, said sealing means including a first and unsecured peripheral portion adapted to be engaged between parts of the housing, and other portions integral with and each extending from the peripheral seal portion inwardly along the spaced peripheral portions of the wear plate to and around portions of the bearing means, said other portions being bonded to the wear plate.

16. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller means, movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly.

17. In a rotary hydraulic machine, gear type impeller means, a housing for said impeller mean-s, movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient and compressible sealing means at the second side of said plate and bearing against the housing providing high and low pres-- sure area-s at the second side of the plate, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly and for preventing high pressure extrusion of the" 1Q seal into the space between the housing and said second side of the plate.

18. In a rotary hydraulic machine, gear type impeller means, a two part housing for said impeller means, movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate means providing high and low pressure areas at the second side of the plate means and sealing between the two parts of the housing, and passage means connecting said high and low pressure areas to high and low pressure regions, respec: tively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly.

19. In a rotary hydraulic machine, gear type impeller means, a two part housing for said impeller means, movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient and compressible sealing means at the second side of said plate means and bearing against the housing providing high and low pressure areas at the second side of the plate means and sealing between the two parts of the housing, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly and for preventing extrusion of the seal into the space between the wear plate and housing.

2%). In a rotary hydraulic machine, gear type impeller means and spaced shafts therefor, a two part housing for said impeller means having bearing means for supporting said shafts, movable wear plate means apertured for the passage of said shafts and having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing and spaced from bearing means, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate means relative to the impeller means, means including resilient sealing means as the second side of said plate providing high and low pressure areas at the second side of the plate, sealing means between the two parts of the housing and around said bearing means, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly.

21. In a rotary hydraulic machine, gear type impeller means and spaced shafts therefor, a two part housing for said impeller means having bearing means for supporting said shafts, movable wear plate means axially spaced; from the bearing means and apertured for the passage of said shafts and having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said wear plate meansrelative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate, sealing means between the two parts of the housing and partially encircling and engaging said bearing means, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together to the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly and to prevent extrusion of the sealing means into the axial space between the bearing means and plate.

22. In a rotary hydraulic machine, gear type impeller means, a two part housing for said impeller means, movable wear plate means having a first side movably abutting against a first side of said impeller means and a second side spaced from and facing the housing, means including a fluid pressure chamber at the second side of said plate for effecting movement of said Wear plate means relative to the impeller means, means including resilient sealing means at the second side of said plate providing high and low pressure areas at the second side of the plate and sealing between the tWo parts of the housing, and passage means connecting said high and low pressure areas to high and low pressure regions, respectively, of said impeller means, said wear plate means and sealing means being bonded together at the second side of the plate means to form a unitary assembly to facilitate manufacture and assembly, and a plate supported by said sealing means in the low pressure region for preventing eX tr'usion of the sealing means therearound.

23. In a rotary hydraulic machine as claimed in claim 22, wherein said sealing means detachably supports said extrusion preventing plate.

24. A Wear plate sealing assembly for end loading the impeller means of a hydraulic machine comprising a wear plate adapted movably to abut against the impeller means and sealing means bonded to a side of the Wear plate opposite the impeller means to facilitate manufacture of the assembly and adapted to define with structure of the machine high and low pressure regions.

25. A wear plate sealing assembly for end loading the impeller means of a hydraulic machine comprising a wear plate adapted movably to abut against the impeller means and resilient compressible sealing means bonded to a side of the wear plate opposite the impeller means to facilitate manufacture of the assembly and adapted to engage structure of the machine to define high and low pressure regions, the said bonded relationship facilitating manufacture and assembly of the machine and preventing move- 12 ment and extrusion of the sealing means relative to the wear plate.

26. A wear plate sealing assembly for end loading the impeller means of a hydraulic machine having a multipart housing comprising a wear plate adapted movably to abut against the impeller means and sealing means bonded to a side of the wear plate opposite the impeller means to facilitate manufacture of the assembly and adapted to define with the housing high and low pressure regions and to provide sealing between the parts of the housing.

27. A wear plate sealing assembly fo end loading bearing means supported impeller means of a hydraulic machine having a multipart-housing comprising a wear plate adapted movably to abut against the impeller means and sealing means bonded to a side of the wear plate oppo-' site the impeller means to facilitate manufacture of the assembly and adapted to define with the housing high and low pressure regions, to provide sealing between parts of the housing and around parts of the bearing means.

28. A Wear plate sealing assembly for end loading bearing means supported impeller means of a hydraulic machine having a multipart housing comprising a wear plate adapted movably to abut against the impeller means and resilient compressible sealing means at a side of the wear plate opposite the impeller means to facilitate manufacture of the assembly and adapted to define with the housing high and low pressure regions, said sealing means including a peripheral unsecured portion to provide sealing between parts of the housing and an inner integral bearing means encircling portion bonded to the plate and providing sealing around parts of the bearing means.

References Cited by the Examiner UNITED STATES PATENTS 2,660,958 12/53 Lauck 103-126 2,682,836 7/54 Orr 103-126 2,809,592 10/57 Miller et a1 103-126 2,816,510 12/57 Jarvis 103-126 2,871,794 2/59 Mosbacher 103-126 3,029,739 4/62 Nagely 103-126 3,050,010 8/62 Thrap et al 103-126 3,096,719 7/63 McAlvay 103-126 3,174,435 3/65 Sisson et al 103-126 DONLEY I. STOCKING, Primary Examiner. 

1. IN A ROTARY HYDRAULIC MACHINE, GEAR TYPE IMPELLER MEANS, A HOUSING FOR SAID IMPELLER MEANS, TRANSVERSELY AND AXIALLY MOVABLE WEAR PLATE MEANS HAVING A FIRST SIDE MOVABLY BUTTING AGAINST A SIDE OF SAID IMPELLER MEANS AND A SECOND SIDE SPACED FROM AND FACING THE HOUSING, MEANS INCLUDING A FLUID PRESSURE CHAMBER AT THE SECOND SIDE OF SAID PLATE FOR EFFECTING MOVEMENT OF SAID WATER PLATE MEANS RELATIVE TO THE IMPELLER MEANS, MEANS INCLUDING RESILIENT SEALING MEANS AT THE SECOND SIDE OF SAID PLATE PROVIDING HIGH AND LOW PRESSURE AREAS AT THE SECOND SIDE OF THE PLATE, AND PASSAGE MEANS CONNECTING SAID HIGH AND LOW PRESSURE AREAS TO HIGH AND LOW PRESSURE REGIONS, RESPECTIVELY, OF SAID IMPELLER MEANS, THE PERIPHERY OF SAID WEAR PLATE MEANS BEING INSET FROM THE HOUSING SUBSTANTIALLY TO THE ROOTS OF THE GEARS FOR A CONSIDERABLE ANGULAR EXTENT IN THE HIGH PRESSURE AREA, WHEREBY THE PRESSURE IN SAID HIGH PRESSURE AREA BIASES THE WEAR PLATE TRANSVERSELY IN THE DIRECTION OF THE LOW PRESSURE ARA AND THE PERIPHERIES OF THE GEAR TEETH ARE OPENED TO THE HIGH PRESSURES TO PROVIDE RADIAL BALANCING OF PRESSURES ACTING ON THE GEARS AND REDUCTION IN DRIVING TORQUE. 